Thread difference between BSPT, BSPP & NPT
Different thread sealing depending on the geographical region,size of the pressure system and the environment. Fox example, In Asia, such as China, Korea, Japan etc normally use BSPT; In U.S, Canada etc always use NPT, then for BSPP thread most popular in UK, Europe, Australia, New Zealand and South Africa. While one sealing style is not inherently better than another each style has its application.
NPT Connections ( National Pipe Thread)- US & Canada
It is according to ANSI/ASME B1.20.1 Pipe Threads. 60 degree of thread angle. NPT male adapters have a taper thread that wedges into the female NPT adapter.
Jennifer Cheng